dlls/ddraw/parent.c

   1 /*
   2  * IParent implementation
   3  *
   4  * Copyright (c) 2006 Stefan Dösinger
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  19  *
  20  * A universal parent interface for everything in WineD3D that doesn't have
  21  * a DDraw counterpart
  22  */
  23
  24 #include "config.h"
  25 #include "wine/port.h"
  26
  27 #include "ddraw_private.h"
  28
  29 WINE_DEFAULT_DEBUG_CHANNEL(ddraw);
  30
  31 /*****************************************************************************
  32  * IUnknown methods
  33  *****************************************************************************/
  34
  35 /*****************************************************************************
  36  * IParent::Queryinterface
  37  *
  38  * It can't query any interfaces, and it's not used for anything. So
  39  * it just returns E_NOINTERFACE
  40  *
  41  * Params:
  42  *  riid: guid of queried interface
  43  *  obj: returns a pointer to the interface
  44  *
  45  * Return values
  46  *  This implementation always returns E_NOINTERFACE and NULL
  47  *
  48  *****************************************************************************/
  49 static HRESULT WINAPI
  50 IParentImpl_QueryInterface(IParent *iface,
  51                            REFIID riid,
  52                            void **obj)
  53 {
  54     TRACE("iface %p, riid %s, object %p.\n", iface, debugstr_guid(riid), obj);
  55
  56     *obj = NULL;
  57     if ( IsEqualGUID( &IID_IUnknown, riid ) ||
  58          IsEqualGUID( &IID_IParent, riid ) )
  59     {
  60         *obj = iface;
  61         IParent_AddRef(iface);
  62         return DD_OK;
  63     }
  64     return E_NOINTERFACE;
  65 }
  66
  67 /*****************************************************************************
  68  * IParent::AddRef
  69  *
  70  * Increases the refcount
  71  *
  72  * Params:
  73  *
  74  * Return values
  75  *  The new refcount
  76  *
  77  *****************************************************************************/
  78 static ULONG WINAPI
  79 IParentImpl_AddRef(IParent *iface)
  80 {
  81     IParentImpl *This = (IParentImpl *)iface;
  82     ULONG ref = InterlockedIncrement(&This->ref);
  83
  84     TRACE("%p increasing refcount to %u.\n", This, ref);
  85
  86     return ref;
  87 }
  88
  89
  90 /*****************************************************************************
  91  * IParent::Release
  92  *
  93  * Releases the refcount, and destroys the object if the refcount falls to 0
  94  * Also releases the child object, if destroyed. That's almost the whole sense
  95  * of this interface.
  96  *
  97  * Params:
  98  *
  99  * Return values
 100  *  The new refcount
 101  *
 102  *****************************************************************************/
 103 static ULONG WINAPI IParentImpl_Release(IParent *iface)
 104 {
 105     IParentImpl *This = (IParentImpl *)iface;
 106     ULONG ref = InterlockedDecrement(&This->ref);
 107
 108     TRACE("%p decreasing refcount to %u.\n", This, ref);
 109
 110     if (ref == 0)
 111     {
 112         TRACE("(%p) Releasing child at %p\n", This, This->child);
 113         if(This->child)
 114             IUnknown_Release(This->child);
 115         HeapFree(GetProcessHeap(), 0, This);
 116         TRACE("Released\n");
 117     }
 118     return ref;
 119 }
 120
 121 /*****************************************************************************
 122  * The VTable
 123  *****************************************************************************/
 124 static const struct IParentVtbl ddraw_parent_vtbl =
 125 {
 126      IParentImpl_QueryInterface,
 127      IParentImpl_AddRef,
 128      IParentImpl_Release,
 129 };
 130
 131 void ddraw_parent_init(IParentImpl *parent)
 132 {
 133     parent->lpVtbl = &ddraw_parent_vtbl;
 134     parent->ref = 1;
 135 }